Zhu-Qing Gao

Piperazine-1,4-diium bis­(hydrogen 2-propyl-1H-imidazole-4,5-dicarbox­ylate) monohydrate

The title compound, C4H12N2 2+·2C8H9N2O4 −·H2O, is a hydrated proton-transfer compound obtained from 2-propyl-1H-imidazole-4,5-dicarboxylic acid and piperazine. The asymmetric unit contains one half-cation, one anion and half a water molecule. There is a centre of inversion at the centre of the cation ring and the water molecule O atom lies on a twofold rotation axis. In the crystal, intermolecular N—H⋯O and N—H⋯N hydrogen bonds help to construct a three-dimensional framework. Almost symmetrical, intramolecular O—H⋯O interactions are also observed.

Di-μ-benzoato-κ3O,O′:O′;κ3O:O,O′-bis[(benzoato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)cadmium]

The dinuclear title compound, [Cd2(C7H5O2)4(C12H8N2)2], lies on a crystallographic twofold axis. The CdII ions are connected by two bridging benzoate anions and each ion is seven-coordinated by five O atoms from three benzoate ligands and by two N atoms from 1,10-phenanthroline. The benzoate ligands adopt two different coordination modes, acting as bidentate and bridging tridentate ligands. The discrete neutral molecules further extend their structure into a three-dimensional supramolecular framework by intermolecular π–π [interplanar distances of 3.392 (4) Å] and C—H⋯π stacking interactions [H–mean plane = 2.567 (4) and 2.781 (4) Å].

Poly[[triaqua­(μ3-4-oxidopyridine-2,6-dicarboxyl­ato)thulium(III)] monohydrate]

In the title coordination polymer, {[Tb(C7H2NO5)(H2O)3]·H2O}n, the TbIII atom is eight-coordinated by a tridentate 4-oxidopyridine-2,6-dicarboxylate trianion, two adjacent monodentate anions and three water molecules, forming a distorted bicapped trigonal–prismatic TbNO7 coordination environment. The anions bridge adjacent TbIII ions into double chains. Adjacent chains are further connected into sheets parallel to (10). O—H⋯O hydrogen bonds involving both coordinated and uncoordinated water molecules generate a three-dimensional network.

Poly[diaqua­tris­(μ4-1,3-phenyl­ene­diacetato)­dicerium(III)]

In the title coordination polymer, [Ce2(C10H8O4)3(H2O)2]n, each CeIII atom is nine-coordinated by eight O atoms from six different 1,3-phenylenediacetate (pda) bivalent anions and one O atom from a coordinated water molecule, forming a distorted tricapped trigonal–prismatic coordination geometry. Eight CeIII ions and twelve pda ligands form a large [Ce8(pda)12] ring, and four CeIII ions and six pda ligands form a small [Ce4(pda)6] ring. The rings are further connected by the coordination interactions of pda ligands and CeIII, generating a three-dimensional supramolecular framework.

Poly[diaqua­bis­(nitrato-κ2O,O′)bis­(1,10-phenanthroline-κ2N,N′)-μ3-succinato-dicadmium]

In the title coordination polymer, [Cd2(C4H4O4)(NO3)2(C12H8N2)2(H2O)2]n, the CdII ion is seven-coordinated within a distorted pentagonal–bipyramidal O5N2 environment. The succinate anions, located on an inversion centre, adopt a bis-monodentate bridging mode, leading to the formation of rods along [100]. The rods are connected by O—H⋯O hydrogen bonds between the coordinating water molecules and nitrate O atoms of adjacent rods; the same type of hydrogen bonds are also observed between water and carboxylate O atoms within the rods. π–π stacking interactions with a minimum plane-to-plane separation of 3.462 (2) Å occur between phenanthroline ligands.

Poly[[triaqua-(μ(3)-4-oxidopyridine-2,6-dicarboxyl-ato)europium(III)] monohydrate].

In the title coordination polymer, {[Ho(C7H2NO5)(H2O)3]·H2O}n, the HoIII atom is eight-coordinated by a tridentate 4-oxidopyridine-2,6-dicarboxylate trianion, two monodentate anions and three water molecules, forming a distorted bicapped trigonal–prismatic HoNO7 coordination geometry. The anions bridge adjacent HoIII ions into double chains. Adjacent chains are further connected into sheets. O—H⋯O hydrogen bonds involving both coordinated and uncoordinated water molecules generate a three-dimensional supramolecular framework.

Di-μ-benzoato-κ3O,O′:O;κ3O:O,O′-bis­[(benzoato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)lead(II)]

In the centrosymmetric dinuclear title compound, [Pb2(C7H5O2)4(C12H8N2)2], two Pb2+ ions are connected by two tridentate bridging benzoate anions. The Pb2+ ion is seven-coordinated by five O atoms from three benzoate anions and two N atoms from the 1,10-phenanthroline ligands. The benzoate anions adopt two different coordination modes, one bidentate–chelating and one tridentate bridging–chelating. The three-dimensional supramolecular framework is achieved by intermolecular π–π stacking interactions, with a shortest centroid–centroid distance of 3.617 (4) Å.

Di-μ-benzoato-κ3 O,O′:O;κ3 O:O,O′-bis­[(benzoato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)lead(II)]

In the centrosymmetric dinuclear title compound, [Pb2(C7H5O2)4(C12H8N2)2], two Pb2+ ions are connected by two tridentate bridging benzoate anions. The Pb2+ ion is seven-coordinated by five O atoms from three benzoate anions and two N atoms from the 1,10-phenanthroline ligands. The benzoate anions adopt two different coordination modes, one bidentate–chelating and one tridentate bridging–chelating. The three-dimensional supramolecular framework is achieved by intermolecular π–π stacking interactions, with a shortest centroid–centroid distance of 3.617 (4) Å.